Field of the Invention
The present invention relates to an identification and/or sensor system having a transmitter that sends query signals by radio to an identification and/or sensor configuration, a receiver that evaluates answer signals sent back by the identification and/or sensor configuration, and resonators provided in the identification and/or sensor configuration for defining at least one parameter to be queried.
Identification and/or sensor systems of that generic type are known, for instance, from German Published, Non-Prosecuted Patent Application DE 42 17 049 A1, corresponding to U.S. application Ser. No. 08/270,931, filed Jul. 5, 1994. They are systems with passive surface wave sensors for ascertaining measured values, in which a transmit and receive device transmits energy by radio in the form of a query pulse to a sensor element contained in the surface wave sensor. Such systems are suitable for contactless measured value detection. The sensor element, which works with acoustical surface waves, and a reference element that also works with acoustical surface waves, are provided for phase discrimination and/or transit time measurements.
Such systems, which use sensor elements that work with acoustical surface waves, known as SW sensor elements, are usable for a great number of variables or parameters to be detected.
If resonators are provided in an identification and/or sensor configuration as elements that define the variables or parameters to be detected, then the answer signals decay with a time function that is defined by the energy decay time of the resonators.